It is known to use rotary jets in a spa to direct a stream of water through one or more nozzles which rotate, to provide a swirling or agitating motion to the water which acts against the users skin and muscle tissue.
Typically, as taught in U.S. Pat. No. 6,123,274 to Perdreau et al., spa jets of this type have a housing which is connected at an inlet to a pressurized water source. A nozzle is supported in a jet barrel in the housing by a radial ball bearing in an open cup-shaped portion of the jet barrel. The nozzle typically has an angular passage, radially offset from the central axis of the housing and jet barrel so that as the water enters the inlet and is caused to exit the passage, the nozzle is rotated on the bearing.
Commonly, debris and hard water deposits become lodged about the ball bearing and between the nozzle and the jet barrel. Over time, the nozzle stops spinning as a result of the buildup. In order to restore proper jet action, the jets must be removed from the spa, dismantled, cleaned and re-assembled. The repair is costly and time consuming and often results in wholesale replacement of the jet.
Others have attempted to design spa jets that minimize clogging of the jet due to debris. U.S. Pat. No. 6,491,238 to Swanson et al. describes a spa jet having a flow guide or baffle which reduces the amount of water and acts to slow down flow of water internally within the jet and reaching the radial ball bearing. This slowing of the water is believed to diminish the amount of debris that reaches the bearing while still maintaining a small flow of water to the bearing to act as a lubricant. A debris pocket defined between the flow tube and the baffle wall acts to collect settled out particulates. While this type of baffle reduces the amount of debris such as plastics, sand, hair, dirt and greases such as from suntan oil, body oils and the like, it does not act to prevent the buildup of scale such as hard water deposits, in at least a portion of the areas having small tolerances, such as between the nozzle and the housing and in the baffles and the bearing races, as a result of the remaining flow of water in these areas.
Clearly, what is required is a nozzle that can maintain rotation within the housing regardless that the environment may be inclined to deposit hard water deposits around the rotating aspects of the jet.